Exercise 1

Which missing data mechanism occurs when the probability of missingness is unrelated to both observed and unobserved data?
Think about a situation where missing data occurs purely by chance.
The correct answer is Missing Completely at Random (MCAR).

Exercise 2

Which missing data mechanism occurs when the probability of missingness depends on the observed data but not on the missing data itself?
Focus on situations where missingness is linked to information already collected but not to the data you are missing.
The correct answer is Missing at Random (MAR).

Exercise 3

Which missing data mechanism occurs when the probability of missingness is related to the unobserved data itself?
Think about situations where the data you are missing is actually influencing whether the data is missing in the first place.
The correct answer is Missing Not at Random (MNAR).

Exercise 4

In a survey, if participants skip questions about their income but answer other questions, what is this an example of?
Think about situations where people are more likely to miss certain types of questions, such as sensitive ones.
The correct answer is Missing Not at Random (MNAR), as missingness is likely tied to the income variable itself.

Exercise 5

What statistical technique can be used to handle data that is Missing at Random (MAR)?
You may have seen methods that allow you to fill in missing values using information from observed data.
The correct answer is multiple imputation or maximum likelihood estimation.